Treatment with antioxidants as an adjuvant in the standard management of patients with sepsis, septic shock and infection with COVID-19 has been suggested (31–34). We studied critically ill patients with septic shock regardless of the etiology and site of infection. All patients had initial low levels of Vit C, which was related with the severity of organ failure and mortality (18). The decrease in Vit C levels confirms the reported hypovitaminosis (< 0.23 µM ascorbic ac/mL) in septic shock (34–37). It may be due to augmented metabolic demand, since intestinal absorption is not compromised in the patients in our study. (36). Vit C restored the normal values of this vitamin and organ function was improved. The best result was found in subjects with pneumonia with significant difference. This finding is in agreement with previous results (38–40). The combined use of Vit C, thiamine and steroids has recently been suggested. It is still necessary to compare if the use of Vit C alone has worse effects than the combinations (41).
In patients with septic shock, the administration of Vit C and MT improved the organ dysfunction assessed by the SOFA score. This finding could be associated to a decrease in the NO3−/NO2− and LPO levels.
The CITRIS-ALI study in patients with acute respiratory failure syndrome, ARFS, and organ failure showed no improvement with Vit C (42). The median time before starting treatment with Vit C was of 5 hours in this study, and markers such as CPR were significantly decreased, which was similar to another study (43). The possible difference with our results could be related to the fact that in the CITRIS-ALI study they started the therapy with Vit C later.
The VITAMINS trial showed no significant difference in the SOFA score, or in days without ventilation at 28 day; however, the use of Vit C lowered mortality (44). In that same study, CRP levels were not decreased, which was probably due to the late administration of Vit C in advanced stages of sepsis before developing ARDS (42). In contrast, we found a decrease in the levels of NO3−/NO2− which is relevant since Vit C inhibits the production of superoxide (O2−) and peroxynitrite, thus preventing abundant NO synthesis, inhibiting mRNA expression and decreasing pathological vasoconstriction (17). These effects might be underlying the clinical benefit. A shorter time of use of vasopressors and a decreased intrahospital mortality was found in patient receiving Vit C (45).
This is the first study of the use of MT in humans with septic shock. Recently MT has been applied in subjects with COVID 19 and it has a high safety profile limiting this virus-related disease. Experimental and clinical studies are required to confirm this hypothesis (31). MT possesses free radical scavenging properties thus protecting cell membrane lipids, cytosol proteins, and nuclear and mitocondrial DNA (23, 24). In our findings, LPO was significantly decreased in the group of patients who received MT which was similar to results in the Galley’s study (25). MT has beneficial effects in experimental cells, plants, and animals; however, its mechanisms of action remain unknown. The functions of the MT receptor relate to its ability as a detoxification agent, thus protecting molecules from the destructive effects of OS in ischemia/reperfusion (stroke, heart attack), ionizing radiation and drug toxicity. In sepsis, the protective effects of MT are associated with the inhibition of the apoptotic processes and reduction of OS.
Production of ROS is increased in an animal model of septic shock (46, 47). This coincides with a lowering of the TAC and a reduction of the activity of superoxide dismutase and GSH peroxidase (48–55). MT reversed morphological damage and increased the activities of antioxidant enzymes (46, 48, 61, 49, 53, 55–60). Therefore, research through blinded clinical trials (62, 63) and multicenter studies with adequate amounts of MT are needed to determine the potential of MT. In this clinical trial, we found a reduction of LPO and its potentially beneficial effect in organ dysfunction. Its use as an adjuvant in septic shock reduces inflammation and oxidation in animal models with respiratory damage induced by infection. MT has positive physiological actions, it is effective and safe for patients with septic shock of any etiology including those infected with SARS-CoV2 (31).
The use of NAC improved the antioxidant capacity and tended to increase GSH although the difference was not statistically significant. This confirms its antioxidant effect through the replacement of GSH deposits (12). NAC was related to decreases in organ failure, confirming previous findings (14).
Other antioxidants such as polyphenols, MT, β-glucan, antioxidants targeting mitochondria, selenium salts, and selenium organ compounds are effective for improving OS in sepsis. The study of their pathophysiological implications justifies the combined therapy with antioxidants and standard treatments.
Vit E tended to decrease LPO and carbonylation. This vitamin protects cell membranes from LPO, ending their chain reaction. It is also an O2− and hydroxyl (OH) sequestrant (64).
In summary, antioxidants benefit subjects with septic shock. Septic shock is triggered by bacterial stimuli, fungi or viruses. In this medical condition, it is necessary to regulate inflammation and other mechanisms that lead to OS (65).